The long-term goal of this project is to examine the influence of probabilistic phonotactics on lexical retrieval during speech production. Recent work has demonstrated that probabilistic phonotactics affects spoken word recognition; however, little research has been conducted on its affects on speech production. Other findings, examining the effects on speech production of phonologically similar neighborhoods - a factor that is highly correlated with phonotactic probability - suggest that phonotactic information may also influence the speed and accuracy of lexical retrieval in speech production. A number of behavioral tasks, including several newly developed methodologies, as well as more conventional methods, will be used to provide converging evidence of the influence of probabilistic phonotactics on lexical retrieval of words and pseudo-words during speech production. The results of these studies using real words and specially constructed non-words will provide important new insights about the representations and general processing principles operating in speech production and perception. A better understanding of normal lexical retrieval could lead to valuable insights about the processes and representations used during lexical retrieval for speech production by clinical populations, including the elderly; hearing-impaired; and patients with aphasias or other neurogenic disorders.